Apparatus for making conical diaphragms



l 645 508 11 1927' c. L. FARRAND ET AL APPARATUS FOR MAKING CONICAL DIAPHRAGMS Filed Nov. 5, 1926 3 Sheets-Sheet 1 INVENTOR5.

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ATTORNEYS Oct. 11, 1927. o 1,645,508

C. L. FARRAND ET AL APPARATUS FOR MAKING CONICAL DIAPHRAGMS Filed Nov. 5, 1926 3 Sheets-Sheet 2 Z 2 r l v 4 a I VENTOR9 ifi/ n4 1927. 1,645,508 Oct, c. 1.. FARRAND ET AL APPARATUS FOR MAKING CONICAL DIAPHRAGMS Filed Nov. 5, 1926 3 Sheets-Sheet 3 I a l f -20 f. I7 I J /4 an H I 1" 4 9 4 3 3 /6 b Patented ea. 11, 1927.

UNITED STATES PATENT OFFICE.

CLAIR L. FARRAND, 0F FOREST HILLS, NEW YORK, AND ERNEST ROSS, OF EAST ORANGE, NEW JERSEY; SAID ROSS ASSIGNOR TO FARRAND CO. INC, OF LONG ISLAND CITY, NEIIV YORK, A CORPORATION OF NEW JERSEY.

APPARATUS FOR MAKING CONIGAL DIAIHRAGMS.

Application filed November This invention relates to the manufacture of so-called double-cone diaphragms for loud speakers.

Many of the radio loud speakers now in use have a paper diaphragm formed by cementing together the base edges of two cones, or a cone and a cone frustum. This type of diaphragm is usually referred to as a double-cone diaphragm.

One object of this invention is to provide improved apparatus which facilitates the assembling and uniting of the two sections of a double-cone diaphragm.

Another object of the invention is to provide an improved process of assembling or uniting the two sections of a double-cone diaphragm.

1n the type of double-cone diaphragm with which this invention particularly deals the sections of the diaphragm are a cone and a cone frustum. The baseedge portions of the diaphragm sections are bent backwardly so that they form between them a peripheral groove or recess for receiving the adhesive. In this recess may also be positioned a filler, such as an ornamental twisted cord'which conceals the joint between the diaphragm sections adds to the ornamental appearance of the finished diaphragm and also assists in producing an effective joint between the diaphragm sections.

The apparatus by which the cone sections are assembled and united comprises a holder for each diaphragm section which are relatively movable towards and away from each other in such a way that the bases of the diaphragm sections may be brought together, and so that the groove at the periphery of the diaphragm will be exposed and accessible. Means are provided for rotating the holders, and an adhesive supply device feeds adhesive into the peripheral groove of the diaphragm driving its rotation. The holders and diaphragm sections are kept slightly separated during their rotation so that the adhesive will penetrate below the base of the groove for the purpose hereinafter described. As the holders rotate, anoperator feeds an ornamental cord into the diaphragm groove on top of the adhesive. The apparatus also preferably includes a heat supply device for heating the joint between the diaphragm sec- 5, 1926. Serial No. 146355.

tions as the diaphragm rotates and also means whereby the holders maybe moved close together, just before the diaphragm is removed from the apparatus, to press the edges of the diaphragm sections into close contact with each other and with the intervening cord.

The accompanying drawings illustrate the improved process, of assembling or uniting the cone sections and also illustrates one form of apparatus in which the process may be carried out. I

In the drawings:

Fig. l is a side elevation. of the apparatus; v

Fig. 2 is an enlarged vertical section taken on the line 22 of Fig. 4;

Fig. 3 is a detail view showing the con nection between the holders for imparting rotation from one to the other;

Fig. 4 is a vertical longitudinal section through the holders and the diaphragm sections;

Fig. 5 is an enlarged perspective view of a hook that is used to assist in holding the diaphragm sections together after they are removed from the apparatus;

Fig. 6 is a vertical section of the diaphragm sections as they appear prior to their insertion in the apparatus;

Fig. 7 is an enlarged detail section showing the manner in which the knife keeps the holders and diaphragm section-s slightly separated while adhesive is being applied;

Fig. 8 is a similar section showing-the adhesive in place;

Fig. 9 is a similar section showing the cord applied on top of the adhesive;

Fig. 10 shows the position which theparts assume after they have been moved into close contact; and T Fig. 11 shows the diaphragm asit appears when removed from the apparatus.

The apparatus shown in the drawings comprises a spider-like casting or holder 1 which is loosely mounted on a. driving shaft 2 but which may be operatively connected with the shaft by a chuck or clutch. This chuck comprises a sliding pin 3 the end of which normally engages in arecess in the shaft 2, as shown in Fig. 4. A spring a yieldingly holds the pin in its lowermost position in which the end of the pin engages in the recess, but by means of a knob 5 the pin may be lifted and held in its raised position when the knob is slightly turned. The shaft 2 is mounted in a standard 6 and is rotated by means of an electric motor 7. A second spider-like casting or holder 8 is mounted to rotate freely on a shaft 9 which is keyed in a standard 10 so that the shaft can slide longitudinally.

Each of the spider-like castings has a hub portion 11 by which the casting may be mounted on its shaft, radially and diagonally extending arms 12 and a ring portion 13 supported by the arms. Each ring portion 13 is provided with an annular beveled seat 14 the inclination of which corresponds with the inclination of the diaphragm section which seats against it, and a second annular beveled seat 15 against which .seats the bentback edge portion of the diaphragm section. lVhen the castings are together the seats 14 form between them an annular space converging towards its periphery to accommodate the angular edge portion of the diaphragm and the seats 15 form between them a V-shaped groove which accommodates the outwardly flaring edge portions of the diaphragm sections.

The extreme end of the shaft 2 has a pin 16 which is adapted to be received by an opening at the apex of one of the diaphragm sections as hereinafter described to hold the diaphragn'i in proper position. The casting 8 has a series of longitudinally extending pins 17 having end portions 18 of reduced diameter. The end portions 18 of the pins are adapted to extend into the smaller opening of the cone frustum to hold this section of the diaphragm in proper position as hereinafter more fully explained.

The standard 10 has pivoted to it a yoke 19 which is adapted to be moved to and from the positions shown in Figs. 1 and 4 by means of a handle 20. The yoke carries a spring pressed pin 21. iVhen the yoke is in the full-line position shown in Fig. 4 the pin presses against a surface 22 on the end of the shaft 9 and places a slight pressure on theshaft to urge the holder 8 toward the holder 1. lVhen the yoke is moved all the way down to the position shown in Fig. 1 the pin 21 engages with a higher surface 23 on the end of the shaft to exert a greater pressure on it for the purpose hereinafter described. When the yoke moves to and from its operative position the pin 21 rides on a track 24. hen the yoke is in the dotted line position shownin Figs. 1 and 4 it is in its inoperative position. and while in this position the casting 8 and its shaft 9 may he slid back through=the standard 10 so that the diaphragm parts may be inserted in place between the castings or removed from them.

An adhesive receptacle 25 is mounted on an arm 26 which is adapted to swing. about the axis of a supporting shaft 27. When the adhesive receptacle is in its operative positon over the holders 1 and 8 its outlet nozzle 28 is in a position to supply a small stream of adhesive to the peripheral groove in the diaphragm. The outlet nozzle may be controlled by means of a needle valve 29 operated by a knob 30. The adhesive in the receptacle may be placed under pressure by a compressed air pipe 31, to force the ad hesive through the outlet nozzle in an even uniform stream.

The adhesive receptacle carries abracket 32 to the lower end of which is pivoted an arm 33 carrying a knife blade 34. The blade 34 is adapted to engage between the diaphragm sections to keep them slightly separated when the adhesive issupplied to the trough or groove at the periphery of the diaphragm. A spring 35 yieldingly holds the arm 33 and the blade tive positions. lVhen the arm and its blade are moved to an inoperative position a pawl 36 engages behind a tooth 37 and holds the knife blade in a raised position. To lower the knife blade the operator removes the pawl from the tooth 37 and the spring 35 moves the outer end of the arm 33 upwardly and moves the blade 34 downwardly.

A heating device shown at 38 supplies heat to the diaphragm parts while they are rotating. This device may comprise a casing 39 in which a steam or hot water coil 40 is located. Air passing upwardly through the casing 39 is heated and is conducted upwardly through a conduit 41. The upper end of the conduit 41 is shaped substantially as shown in Figs. 1 and 2 so that it partly encloses the lower portion of the holders 1 and 8.

.A few other instrumentalities used during the process of uniting the diaphragm sections will be referred to and described as the various steps of assembling the diaphragm parts are explained.

hen the parts of the diaphragm are Cu be positioned in the apparatus the operator moves the holder 8 aw y from the holder 1 unless these parts are already in this position. To permit this the yoke 19 should be in its raised position as shown by dotted lines in Figs. 1 and 4. At this time the adhesive feed is inoperative because the nee dle valve 29 is in its lowermost position and the knife blade 34 is held in its raised position. l

Vfhen the diaphra 'm sections reach the apparatus they are in substantially the condition shown in Fig.- 6 and have previously been placed in that condition in other ma.- chines. One section comprises a cone 42 and the other section comprises a frustum of a none 43. Each section of the diaphragm is 34 in their opera Ill creased near its edge so that the edge portion tends to, or actually does, flare outwardly as shown at The cone 42 has a small opening 45 at its apex. The edge of the small opening of thecone frustum 43 is held in clamping rings 46 which are subsequently used to mount the diaphragm on its supporting base.

Before the cone 42 is positioned in its holder, a small hook shown in Fig. 5 is positioned in the opening 45 at the apex of the cone. This hook may comprise a piece of wire 47 soldered to a washer-like member 48. \Vhen the hook is positioned in the opening 45 the washer 48 abuts against the out i' surface of the apex of the cone. The cone 42 is then positioned on the holder 1 by slipping the opening 45 at the apex of the cone over the pin 16 on the end of the shaft 2. The pin 16 also passes through the opening in the center of the washer, and to accommodate the wire 47 the pin 16 is slotted as shown at 49. The edge portion of the cone 42 will then be resting against the annular beveled seat 14 on the holder 1.

Before the cone frustum 43 is positioned in its holder an elastic band 50 is applied. diametrically across the clan'iping rings 46.

' This may be done by placing one end of the elastic band over a screw 51, which forms a part of the clamping ring structure and which is subsequently used as attaching means for a knob and by attaching the other end of the elastic band by means of a hook 52 to an opening 53 in the clamping ring structure. The cone frustum 43 is then positioned in the holder 8 by slipping the clamping rings 46 over the ends of the pins 17. The edge portion of the cone frustuln will then be resting against the annular beveled seat 14 on the holder 8.

The operator at this point may give each holder one or more revolutions by hand while holding apiece of wood or the like against the bent back edge portion 44 of the corresponding diaphragm section. This is to make sure that the edge portion 44 of each diaphragm section is bent back as far as it will go and so that it will seat against its seat 15 on the holder. he

operator now lowers the knife blade 34 and then moves the holder 8 towards the holder 1 as far as it will go. He then moves the yoke 19 to the position shown in Fig. 4 in which the pin 21 presses against the surface The holder 8 will then be yieldingly pressed towards the holder 1 and the knife blade 34 will intervene between the diaphragm sections at the creases as clearly shown in Fig. 7. The motor 7 is then started if it is not already operating and the chuck 3+5 is lowered to opera tivelv connect the holder 1 with its shaft 2. The holders then start rotating. In order to insure that the holders rotate in unison and that there will be no slippage between them a pin shown at 54 in Fig. 3 which is slidaloly mounted in-the-periphery of one of the holders engages in a small opening in the other holder. This pin may be moved to its operative position-by the operator at any convenient time after the two holders are moved towards each other. It should also be explained at this point that each diaphragm section has a small rectangular opening 55 (Fig. 2) formed in its periphery to accommodate certain supporting rods which in the finished speaker pass downwardly from the clamping rings 46, through the interior of the diaphragm structure and then through the openings 55 to the supporting base. The diaphragm sections are so placed in the holders 1 and 8 that these openings 55 come adjacent to the pin 54 so that the pin does not have to ponetrate through a. structural part of the dia phragm sections. This pin also insures that the diaphragm sections will rotate with the holders because the pin will abut against one of the radial edges of the opening 55 and positively rotate the diaphragm sections with the holders.

The operator now turns on the supply of adhesive which may be liquid celluloid, and as the holders rotate the adhesive is fed into the trough or groove formed by the bent back edges 44 of the diaphragm sections. The knife blade 34 holds the 'diaphragm sections apart just far enough to allow some of the adhesive 56 to penetrate below the base of the groove as shown at 57 in Fig. 8. The advantage of this is as follows. lVhen the peripheral portions 44 of the diaphragm sections are bent backwardly the paper is likely to fracture or crack slightly at the crease. Ift-his is too pronounced. and if all of the adhesive is at the outer side of the creases then the joint would not be very effective. However, if the adhesive penetrates inwardly beyond the creases as shown at Fig. 8, the diaphragm. sections are united at both sides of. the

creases. I

The holders 1 and 8 rotate toward the operator in the direction of the arrow shown in Fig. 2. During rotation of the holders the operator feeds an ornamental cord 58 into the groove between the bent back portions 44 of the diaphragm sections, it being understood that the adhesive. is supplied to this groove at a point in advance of the point where the operator positions the cord in the groove so that the cord will be positioned on top of the adhesive. In order to facilitate the positioning of the cord in the groove the holder '8 is provided with a spring clamp 59 for holding one end of the cord. WVhen the adhesive feed is started the clan' p 59 is preferably adjacent to the ad; hesive receptacle so that by the time the ill Iii

clamp 59 reaches the operator adhesive has already been applied to the groove extend ing from a point opposite the clamp 59 back to the adhesive receptacle. W hen the clamp 59 reaches the operator he quickly applies one end of the cord under the spring clamp 59 and then passes it around a projecting pin 60 on the periphery of the same holder and thereafter feeds the cord into the groove as the holders rotate. The operator presses the cord firmly into the groove with his hands during the rotation of the holders. The operator stops the stream of adhesive when it has been supplied to the entire groove. Then the cord has been applied to the entire groove the operator stops the machine and then the second end of the cord is passed around a second pin 61 on the holder 8 and is then positioned in a second spring clamp 62. During the application of the cord to the groove and when the holders have rotated far enough to bring the forward end of the cord close to the knife blade 34 the operator quickly throws the knife blade out of operation so as to permit the cord to pass under it. It will be noted, however. that the cord now serves to hold the sections of the diaphragm slightly separated in somewhat the same manner as the knife blade performs this function as shown in Fig. 9. During the rotation of the holders the hot air supplied by the conduit ll partly sets the adhesive.

Before the diaphragm is removed from the apparatus the operator moves the yoke 19 to the position shown in Fig. 1 in which the pin 21 engages with the surface 22* This 'applies greater endwise pressure to the holder 8 and causes it to move into closer engagement with the holder 1. The result is that the two sections of the diaphragm are moved into close contact with each other and into close contact with the cord 58 as shown in Fig. 10. The holders may now be rotated for several more revolutions if so desired so that the hot air-supplied by the conduit 1% will further set the adhesive while the parts are in the position just described. The machine is again stopped and before the diaphragm is removed from the apparatus the operator applies the elastic band over the end of the hook ll. T his elastically attaches the two sections of the diaphragm together and prevents slippage or movement of the diaphragm sections relative to each other when they are removed from the apparatus. Just prior to the rcmoval of the diaphragm from the apparitus the operator removes the ends of the cord from the spring clamps 59 and 62 and removes the ends of the cords from engage ment with the pins and-61. If desired temporary clamps may be applied to the ends of the cord and to the edges of the diaphragm itself to hold the cord in proper position when the diaphragm is being removed and during its subsequent handling. The yoke 19 is now moved to its inoperative position and the holder 8 is moved backwardly away from the holder 1. .'.he diaphragm structure'is then removed from the apparatus at which time it has the appearance shown in Fig. 10. It might be further dried. on a drying rack if so desired after which the elastic band and the hook 47 are removed.

Certain details of the loud speaker itself, disclosed but not claimed herein, are claimed in other pending applications.

lVe claim:

1. The process of uniting the two conical parts of a double cone diaphragm which comprises bending back the peripheral edge portion of each conical part, placing the conical'parts in juxtaposition so that said bent back peripheral portions form a groove between them, and rotating the two conical parts while feeding adhesive into aid groove.

2. A process in accordance with claim 1 in which heat is applied to the conical parts during their rotation.

3. A process in accordance with claim 1 in which a filler such as a cord is fed into the groove on top of the adhesive.

4. A process in accordance with claim 1 in which a filler such as a cord is fed into the groove on top of the adhesive and in which heat is applied to the conical parts during their rotation.

55. The process of uniting the two conical parts of a double cone diaphragm which comprises bending back the peripheral edge portion of each conical part, placing the conical parts in juxtaposition so that said bent back peripheral portions form a groove between them, rotating the two conical parts while feeding adhesive into said groove, and holding the meeting edges of the conical parts at the base of the groove slightly sepa rated at least in the vicinity of the adhesive feed to allow the adhesive to penetrate be low the base of the groove.

6. A process in accordance with claim 5 in which pressure is finally applied to the two conical. parts to move them into close proximity.

'7. A process in accordance with claim 5 in which tiller such as a. cord is fed into the separated groove r. r the adhesive is ap- -lirirl V punteat their base edges and elastically interconnecting the two parts after they are cemented together so that they will be elastically clamped together during subsequent handling.

10. The process of uniting the two conical parts of a double cone diaphragm which comprises cementing the parts together in a suitable machine, and elastically interconnecting the two parts after they are cemented together and prior to their removal from the machine so that they will be elastically clamped together during their removal from the machine.

11. The process of uniting the two conical parts 01 a double cone diaphragm which comprises cementing the two parts together at their base edges and applying a temporary binding device to the diaphragm parts to hold them together during their removal from the machine.

12. Apparatus for uniting the two conical parts of a double cone diaphragm which comprises a holder for each conical part 01 the diaphragm, a mounting for at least one of said holders permitting relative move ment of the holders toward and away from each other and means for rotating said holders.

13. Apparatus in accordance with claim 12 in which at least one of the holders is provided with a pin adapted to engage in an opening at the apex of one of the conical parts of the diaphragm.

1%. Apparatus for assembling the two parts of a double cone diaphragm one part of which is a cone trustum, which comprises a holder for each part of the diaphragm, a mounting for at least one of said holders permitting relative movement of the holders toward and away from each other, and means for rotating said holders, at least one of said hold rs being'provided with fingers adapted to engage with the inner edge of said cone frustum.

V 15. Apparatus tor assembling the two parts of a double cone diaphragm one of which parts is a cone and the other a cone :trustum which comprises a holder for the cone, a holder for the cone frustuin, a mounting for at least one of said holders which permits relative movement of the holders toward and away from each other, and means for rotating said holders, one of said holders being provided with a pin adapted to engage in a. central opening at the apex of the cone, and the otherholder being provided with fingers adapted to engage with the inner edge of the cone trustum.

peripheral portion of the parts of the diaphragm during rotation of the holders.

17. In apparatus in accordance with claim 12 an adhesive-supply device for feeding adhesive to the peripheral portion of the con- 'cal parts of the diaphragm during rotation of the holders, and means acting on the peripheral edges of the conical parts of the diaphragm in advance of the adhesive 'feed for slightly separating them.

18. In apparatus in accordance with claim 12 an adhesive-supply device for feeding adhesive to the peripheral portion of the conical parts of the diaphragm during rotation of the holders and a spring-pressed knife acting on the peripheral edges oi the conical parts of the diaphragm in advance of the adhesive feed for slightly separating them.

19. Apparatus for assembling the two conical parts of a double cone diaphragm which comprises a holder for each part of the diaphragm, a. mounting for at least one of said holders permitting relative movement of the holders toward and away from each other, means to rotate the holders, ad hesive supply means for supplying adhesive at the peripheral portion of the holders, means for keeping said holders slightly separated at least in the vicinity of the adhesive feed, and manually controlled pressure applying means ior one of said holders whereby final pressure may be applied to said holder to force together the edges of the parts of the diaphragm.

20. Apparatus in accordance with claim 12 in'which at least one of the holders is provided with a cord clamp whereby the end 01 a cord'may be fastened therein and fed to the peripheral et ges of the diaphragm during their rotation.

21. Apparatus in accordance with claim 12 in which at least one of the holders is provided with one clamp for holding the end oi a cord adapted to be fed to the peripheral edges of the parts of the diaphragm during .rotation of saidholders, and a second clamp to which the other end of said cord may be clamped.

In testimony whereof we afi'iX our signatures.

CLAIR L. FARRAND. ERNEST ROSS. 

